Vacuum-breaking valve for a refrigerated compartment

ABSTRACT

A vaccum-breaking valve comprising: a tubular body ( 10 ) mounted through one of the walls (P) of the cabinet (G) and having inner ( 11 ) and outer ( 12 ) ends, a valve seat ( 15 ) defining a fluid communication between the inside and the outside of cabinet (G); and a seal constantly biased towards a closed position, blocking said fluid communication and dispalceable towards an open valve position. The seal comprises a slide ( 20 ), which is axially and slicingly mounted through the valve seat ( 15 ) and has a surrounding sealing ring ( 25 ), which is seated against the valve seat ( 15 ) when the slide ( 20 ) is displaced to the closed seal position, the slide ( 20 ) being provided with at least one air passage ( 24 ) interconnecting the upstream and downstream sides of the valve seat ( 15 ) when the slide ( 20 ) is in the open seal position.

RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §371 based onInternational Application No. PCT/BR01/00025, filed Mar. 15, 2001, whichwas published on Jun. 20, 2002, as International Publication No. WO02/48626, claiming priority to Brazilian Patent Applications Ser. No.PI0006442-4, filed Dec. 11 2001, of which are incorporated herein byreference.

FIELD OF THE INVENTION

The present invention refers to a construction of a vacuum-breakingvalve to be used in refrigeration appliances in general, such asvertical freezers and refrigerators combined with a freezingcompartment, in order to increase the internal pressure inside theseappliances and facilitate the reopening of the door.

BACKGROUND OF THE INVENTION

In refrigeration appliances, such as vertical freezers and refrigeratorscombined with a freezing compartment which have, inside a cabinet G, atleast one compartment, which is hermetically closed with good sealingand thermically insulated and inside which the temperature is lower thanthe temperature of the surrounding external environment, there isobserved an undesired effect which tends to make difficult the immediatereopening of the door of said refrigeration appliance after it has beenopened and closed.

This phenomenon is due to the decrease in the pressure of the air massadmitted to the inside of the refrigerated compartment upon the openingof the door, which is inherent to the decrease in temperature of saidair mass after the closing of the door, producing an unbalance betweenthe internal pressure, which is lower, and the external pressure, whichis higher.

As a result, a strong vacuum is produced inside the cabinet, resultingin a force on the door acting to keep it closed, and consequently makingdifficult the immediate reopening thereof. At present, it is recommendedthat the user wait a few minutes before reopening the door.

In order to overcome this problem and allow users to reopen the cabinetdoor immediately after its closing and with less effort, a device knownas vacuum-breaking valve is used, whose function is to promote theequalization of the internal and external pressures. This valve iscomprised of a generally cylindrical and rectilinear tubular body, whichcrosses one of the walls of the cabinet G of the refrigerationappliance, in order to promote a fluid communication between the insideand the outside thereof and to allow, in certain occasions (notably whenthe internal pressure is lower than the external pressure), the externalair to enter the cabinet, thus increasing the internal pressure until itbecomes close to the external pressure, represented by the atmosphericpressure. The tubular body is open on its inner side and has on itsouter side a sealing system consisting of a movable seal, which isactivated by gravity and is movable between a sealing position when inrest, seated on a valve seat and promoting the sealing of the airpassage, and a spaced position, when it is maintained suspended andspaced from the valve seat, due to the difference between the externaland internal pressures of the cabinet, thus enabling the air flow to theinside thereof.

The tubular body of the valve may be formed of a thermically conductivematerial, having its outer end arranged in order to define a heatcollector to collect thermal radiation coming from a heat sourceavailable in the refrigeration appliance and which can be defined by thecompressor. This construction allows the tubular body of the valve to bekept warm enough to prevent ice formation therein, due to thecondensation of the air that enters when the valve is open, withoutinterfering with the cooling inside the cabinet. This construction isdescribed in the patent application BR PI0001249-1, of the sameapplicant.

While operating adequately, mainly when the tubular body of the valve isbuilt of a material with good thermal conductivity and is kept slightlyheated, the constructive arrangement of the seal suggested in the priorart uses the force of gravity to keep the seal, in the form of a sphere,seated on the valve seat, sealing the fluid communication between theinside and the outside of the cabinet.

Due to the fact that the seal is gravitationally and verticallydisplaced between a closed position, seated on the valve seat, and anopen position, elevated in relation to the valve seat by action of thepressure difference between the inlet and outlet ends of the tubularbody, it should be built in order to be light enough to be suspended bythe “vacuum” formed inside the cabinet, particularly when the userstarts the movement of reopening the door immediately after a closingthereof.

The construction of the usual spherical seal with a light spherical bodyis relatively costly and complex, besides allowing surfaceirregularities, such as barbs, to be formed on the spherical body of theseal. The low weight of these seals and the presence of surfaceirregularities thereon makes little efficient the closing of the valveseat only by the gravitational seating of a very light and small sphereagainst the sealing seat of the valve. On the other hand, the use of aheavier seal would make impracticable its upward displacement bypressure difference.

Therefore, in these known solutions, the construction of the seal isdetermined by the weight limitations, which weight should also bedetermined so that the valve only opens when the user starts a doorreopening, in order to avoid that the presence of the pressuredifference after each closing of the door causes the opening of thevalve and the admission of external humid air inside the cabinet, evenwithout an immediate reopening of the door. The adequate operation ofthe valve thus depends on the weight of the seal and the precision ofits finishing, even if the limit weight is insufficient to promote anefficient sealing in the closed valve condition.

An inadequate sealing of the valve seat allows the occurrence of a flowof external humid air to the inside of the cabinet any time the internalpressure thereof is lower than the external pressure, causing undue iceformation inside the refrigerated compartment.

OBJECTIVE OF THE INVENTION

It is the object of the present invention to provide a vacuum-breakingvalve for refrigerated compartments of simple construction and reliableoperation, which allows the admission of external air to the inside ofthe cabinet to which it is installed only when the cabinet door isreopened by the user, immediately after a previous closing, assuring ahigh degree of sealing when in a closed position.

DISCLOSURE OF THE INVENTION

The objective above is achieved with the provision of a vacuum-breakingvalve for a refrigerated compartment closed by a door operated by theuser, said valve comprising: a tubular body mounted through one of thewalls of the cabinet and having inner and outer ends, which arerespectively open to the inside and the outside of the cabinet; a valveseat provided on the outer end of the tubular body and defining a fluidcommunication between the inside and the outside of the cabinet; and aseal mounted to the tubular body and constantly biased towards a closedposition, in which it is seated against said valve seat, blocking saidfluid communication and movable towards an open position, spaced fromthe valve seat, establishing said fluid communication.

According to the invention, the seal comprises a slide, which is axiallyand slidingly mounted through the valve seat and has a closed endportion and an opposite end portion, which are interconnected by aperipheral lateral contour carrying a surrounding sealing ring, which isseated against the valve seat when the slide is displaced to the closedseal position and which is spaced away from the valve seat when theslide is displaced to the open seal position, the slide being providedwith at least one air passage connecting the opposite end portion of theslide with a region of the peripheral lateral contour located betweensaid opposite end portion and the surrounding sealing ring, said airpassage being upstream the valve seat when the slide is in the closedseal position and interconnecting the upstream and downstream sides ofthe valve seat when the slide is in the open seal position.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described below, with reference to the appendeddrawing, in which:

FIG. 1 is a rather schematic representation of a vertical longitudinalsection of the vacuum-breaking valve of the present invention in theclosed position and installed through a wall of a refrigerated cabinet;

FIG. 2 is a view similar to that of FIG. 1, illustrating the valve inthe open condition.

BEST MODE OF CARRYING OUT THE INVENTION

As mentioned above, the present vacuum-breaking valve is of the typecomprising a tubular body 10, which is preferably cylindrical and formedof a thermically conductive material, mounted through one of the walls Pof a refrigerated cabinet G, closed by a door (not illustrated) to beoperated by the user.

The tubular body 1 has an inner end 11 open to the inside of cabinet Gand an outer end 12 open to the outside of the cabinet and preferablyarranged in order to define a collector for the heat irradiated by thecompressor of the refrigeration system or by any other heat sourceavailable to the refrigeration appliance.

Inside the outer end 12 of the tubular body 10 a valve seat 15 isincorporated, defining a generally circular opening in order toestablish fluid communication between the inside and the outside ofcabinet G through the tubular body 10.

In the illustrated embodiment, the valve seat 15 is defined by anannular flange internally incorporated in an elongated portion 13 of theouter end 12 of the tubular body 10, which elongated portion 13coaxially projects from the outer face of the wall P of cabinet G andmay present a contour that is geometrically equal to, similar to ordifferent from the rest of the tubular body 10 and may be constructed asa separate piece.

The vacuum-breaking valve further comprises a seal in the form of aslide 20, which is axially and slidingly mounted through a valve seat 15so that it may be displaced between a closed position, in which itblocks the valve seat 15 and the fluid communication between the insideand the outside of cabinet G, and an open position, allowing theestablishment of said fluid communication through the valve seat 15.

In the illustrative configuration shown in the drawings, the slide 20takes the form of a an elongated prismatic body having a cross-sectionsimilar to and slightly smaller than the cross-section of the valve seat15, preferably cylindrical, said slide having a closed end portion 21and an opposite end portion 22, which are interconnected by a peripherallateral contour 23. In the illustrated construction, the slide 20 istubular, with the opposite end portion 22 opened and with the peripherallateral contour 23 provided with at least one window 24, which defines,with the hollow interior and the open opposite end portion 22, an airpassage, whose function will be described below.

The slide 20 carries, externally, on its closed end portion 21, asurrounding sealing ring 25 located downstream the valve seat 15 andseated against the latter when the slide 20 is displaced to the closedseal position, blocking the fluid communication between the inside andthe outside of cabinet G. The sealing ring 25 is preferably built of anelastomer, in order to facilitate the achievement of a high level oftightness at the interfaces thereof with the slide 20 to which it ismounted and with the valve seat 15 when seated thereon.

The positioning of the valve seat 15 and sealing ring 25 on therespective parts that carry them is made in order that, when the slide20 is in the closed seal position, with the sealing ring 25 seatedagainst the valve seat 15, the opposite end portion 22 of the slide 20remains markedly projected outwardly from the tubular body 10.

In order that the slide 20 be constantly biased towards the closed sealposition (FIG. 1), a spring 30 is provided around the slide 20 andupstream the sealing ring 25 and has an end seated against a stop 22 aincorporated to the opposite end portion 22 of the slide 20 and theother end seated against the outer end 12 of the tubular body 10.

The spring 30 is dimensioned to be compressed, allowing the displacementof the slide 20 towards the tubular body 10, spacing the sealing ring 25from the valve seat 15 and opening the valve when a reopening of thecabinet door is started immediately after a previous closing.

The spring 30 is dimensioned to yield only upon the sudden increase ofthe level of “vacuum” or of the sub-pressure present in cabinet G soonafter the closing of the door, when the user starts an immediatereopening. If the door is not reopened, the sub-pressure level presentsoon after a closing of the door is not sufficient to provide, on theslide 20, enough axial force to compress the spring 30.

While only one embodiment of the vacuum-breaking valve has beenillustrated, it should be understood that modifications could be madewithin the same constructive concept disclosed herein. For example, theslide 20 is not necessarily tubular, since each air passage may beformed by a respective longitudinal groove provided on the lateralperipheral contour 23 of the slide 20, upstream the sealing ring 25. Thespring 30 may also take different forms, as long as it assures theclosing of the valve during the usual operation of cabinet G, allowingits opening only when a reopening of the door is started immediatelyafter being closed.

When the slide 20 is displaced towards the open seal position, eachwindow 24 occupies a position at least partially located downstream thevalve seat 15 (FIG. 2), establishing a fluid communication between theinside and the outside of cabinet G through the tubular body 10,valveseat 15 and each air passage 24, 22 provided on the slide 20.

The constructive arrangement described above allows the door to beeasily reopened by the user, without the need of additional effort orspecial handles for increased manual grip, besides allowing an efficientsealing of the valve when in the closed position.

1. A vacuum-breaking valve for a refrigerated cabinet closed by a dooroperated by the user, said valve comprising: a tubular body mountedthrough one of the walls of the cabinet and having inner and outer ends,which are respectively opened to the inside and to the outside ofcabinet; a valve seat provided on the outer end of the tubular body anddefining a fluid communication between the inside and the outside of thecabinet; and a seal mounted to the tubular body and constantly biasedtowards a closed position and seated against said valve seat, blockingthe valve seat, and displaceable towards an open position, spaced fromthe valve seat, opening the valve seat; wherein the seal comprises: aslide axially and slidingly mounted through the valve seat and has aclosed end portion and an opposite end portion, which are interconnectedby a peripheral lateral contour carrying a surrounding sealing ring,which is seated against the valve seat when the slide is displaced tothe closed seal position and which is spaced away from the valve seatwhen the slide is displaced to the open seal position; wherein the slidebeing provided with at least one air passage connecting the opposite endportion of the slide with a region of the lateral peripheral contourlocated between said opposite end portion and the sealing ring, said airpassage being upstream the valve seat when the slide is in the closedseal position and interconnecting the upstream and downstream sides ofthe valve seat when the slide is in the open seal position, said slidehas a tubular shape, with the opposite end portion axially opened, eachair passage being defined by a window provided on the peripheral lateralcontour, connecting the latter with the open opposite end portion of theslide.
 2. The valve, according to claim 1, characterized in that theslide is constantly biased towards the closed seal position by action ofa spring with its ends respectively acting against the opposite endportion of the slide and the outer end of the tubular body.
 3. Thevalve, according to claim 2, characterized in that the spring isprovided around the peripheral lateral contour of the slide upstream thesealing ring.
 4. The valve, according to claim 1, characterized in thatthe slide has a cross-section similar to and slightly smaller than thecross-section of the valve seat.
 5. The valve, according to claim 1,characterized in that the valve seat is defined by an annular flangeinternally incorporated in an elongated portion of the outer end of thetubular body.
 6. The valve, according to claim 5, characterized in thatthe elongated portion is coaxial to the tubular body.
 7. Valve,according to claim 1, characterized in that the sealing ring is anelastomer.